In this paper, the adsorption process of methylene blue has been investigated on microcline particles as a function of particle size and temperature. The characterization of microcline in the particle size ranges of 1−71 μm and 71−315 μm gained by sieving was proved using X-ray diffraction (XRD) and scanning electron microscopy combined with energy-dispersive detector (SEM-EDS) in powder form, over laser diffraction measurements in aqueous suspension. The optimum dosage of adsorbent was 13.5 g/L in dye adsorption and the adsorption isotherms on both microcline size fractions were determined at this adsorbent concentration. The maximum adsorption capacities were in the range of 1.5–3.1 mg g⁻¹ on microcline particles with supplementing evaluation of isotherms using the Langmuir model. Considering the problems of linearization of equations, the non-linear least-squares estimation can be strongly recommended for modeling adsorption-equilibrium. The adsorption isotherm determined at elevated temperature of 60−65 °C represents a breakpoint at around 20 mg L⁻¹ of equilibrated dye concentration due to performing of a potential process of dye self-association. According to our experiments, the increase in temperature has an adverse effect on adsorption.

The adsorption capacities of alginate, chitosan and immobilized Spirulina platensis-maxima cells were studied in a continuous packed-bed column, under dynamic condition. The composition of alginate and chitosan beads was optimized. Various operating conditions were applied; the effect of flow rate, column height and initial metal ion concentration were investigated. The alginate beads have the highest adsorption capacity for Cu(II), Cd(II) and Pb(II) ions, 3.4, 2.3 and 3.1 mmol g⁻¹ per dry weight, respectively. The alginate-Spirulina system has slightly decreased adsorption capacity 3.1, 1.9 and 3 mmol g⁻¹. The uptake of Cu(II), Cd(II) and Pb(II) by chitosan and chitosan-Spirulina beads is 0.8, 0.9, 0.7 and 1, 0.8, 0.6 mmol g⁻¹. The Thomas and Yoon–Nelson models have been applied to analyse the breakthrough data. The results indicate feasible reuse of the beads at least in five sorption cycles.